A base station antenna is configured to convert a radio frequency signal into an electromagnetic wave signal and radiate the electromagnetic wave signal to space, or, receive an electromagnetic wave signal transmitted from a terminal, convert the electromagnetic wave signal into a radio frequency signal, and output the radio frequency signal to a base station.
Each base station antenna controls an area with a certain range (referred to as a sector or a cell) and radiates or receives an electromagnetic wave within the area. A radiation radius may be controlled through a method of controlling a downtilt of a major lobe, where the larger the downtilt of the major lobe is, the smaller the radiation radius is. Further, a center of an area covered by the sector of the cell may be controlled by controlling a horizontal direction of the major lobe of the antenna, and a horizontal coverage range of the radiation may be controlled by controlling the horizontal beam width of the major lobe.
An active antenna system (AAS) refers to a system formed by integrating an active transceiver and an antenna, which is a new type of a base station architecture. The AAS, as compared with a conventional antenna system, reduces the feeder loss, makes it more convenient to adjust a wave beam of an antenna, and meanwhile has certain advantages at the utilization rate of frequency spectrum resources. Moreover, iron towers or station locations, as finite resources (for example, load bearing of an iron tower is finite and roof space is finite; European and American residents, due to health awareness, are very sensitive to the number and the size of antennas, and the charge of a station location is strongly related to the charge of an owner, so only a small amount of antennas can be installed on a tower or a station location with the foregoing limitation factors), are expected to be shared or reused as far as possible.
However, in the prior art, one antenna only can be independently used in a passive antenna system or in an active antenna system rather than be used in the active antenna system and the passive antenna system at the same time. Alternatively, two types of antennas are only integrated into the same antenna device. Two groups (columns) of antennas completely independent of each other are set in the same antenna, and the adjustments of the downtilts of the two groups (columns) of antennas do not affect each other, but elements are not shared therein, so antenna resources are wasted.